Analysis of concrete structures deteriorated by alkali-aggregate reaction: case study

Abstract

This research aims to analyze the alkali-aggregate reaction with the case study of a waterfront structure pier, a reinforced concrete structure located in a marine environment in Brazil. In the present work is done a literature review on the subject of alkali-aggregate reaction, focusing on Brazilian standards, addressing the chemical mechanism, risk analysis and prevention of this pathological phenomenon. That said, petrographic analyses are also carried out for the characterization of the aggregates used in the structures of mooring dolphins of that pier. The results obtained in laboratory tests reveal the presence of characteristic minerals of the alkali-aggregate reaction in Dolphin C. However, the alkali-aggregate reaction has, as one of its features, the heterogeneous distribution along the affected structures, reason why it is very difficult to establish their degree of development and evolution stage. Therefore, it is not possible to define if the expansive process evidenced in Dolphin C will still be occurring over the years.